Boiler.



PATENTED FEB; 19, 1907. S. SMITH.

BOILER.

APPLICATION FILED DEO.16, 1905.

3 SEEETS-SHEBT 1.

ms NORRIS PETERS Cc, WASHINGTON. a, c.

PATENTED FEB. 19, 1907.

S; SMITH.

BOILER.

APPLICATION FILED 1330.16, 1905.

3 SHEETS-SHEET 2.

ms NORRIS P5 15123 cm, wxsnmnrou, D c,

I PATENTED FEB. 19, 1907.

S. SMITH.

BOILER.

0N ED D SIDNEY SMITH, OF CAMBRIDGE, MASSACHUSETTS.

BOILER.

Specification of Letters Patent.

Patented Feb. 19, 1907.

Application filed December 1 Sefifll 1 Toall whom it may concern.-

Be it known that I, SIDNEY SMITH, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in BoilerSettings and Boilers, of which thefollowing is a specification.

This invention relates to steam-boilers and casings or settingstherefor; and it has for its object to provide certain improvementslooking to the efficiency, safety, and durability of the boiler.

The invention consists in the several improvements which I will nowproceed to describe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a rear end view of a boiler-setting and a system offeed-water-circulating pipes constructed in accordance with myinvention. Fig. 2 represents a longitudinal section on line 2 2 of Fig.1, the boiler being shown in side elevation. Fig. 3 represents a sectionon line 3 3 of Fig. 2. Fig. 4 represents a section on line 4 4 of Fig.2. Fig. 5 represents a sectional detail hereinafter referred to. Fig. 6represents a section on line 6 6 of Fig. 5.

The same letters of reference indicate the same parts in all thefigures.

In the drawings, 12 represents a boiler, which is preferably cylindricaland has the ordinary fire tubes or flues 13 extending through thewater-space of the boiler. The boiler is inclosed in a brickwork casingor setting, which comprises side walls 14 14 and an arch 15, supportedby the side walls and covering the top portion of the boiler. Theportion 16, Fig. 2, of the rear end wall of the casing adjoining thearch 15 is in close proximity to the rear head of the boiler, as shownin Fig. 2, the lower portion 17 of the rear wall being offset andseparated from the rear head of the boiler by a threat 18, through whichthe products of combustion pass from the chamber 19 behind thebridgewall 20.

In accordance with my invention I form an air-space 21 between the arch15 and the upper portion of the boiler, said space extending between theend wall 16 and the rear head of the boiler. The said airspace coverspractically the entire area of the boiler which is in contact with thelive steam within the boiler. A body of dead air is confined in the saidair-space by means of packing or cut-oil strips of material which is anon-conductor of heat, such as asbestos. In this embodiment of myinvention I have shown this packing material or cut-off as comprising,first, two longitudinal strips 22, interposed between the side walls andthe lower edges of the arch 15, said strips projecting inwardly from theside walls and having upwardly-turned edges bearing against the sides ofthe boiler at or near the water-line; secondly, an arched transversestrip 23, interposed between the forward portion of the arch 15 and thecorresponding portion of the boiler, said strip 23 bestriding the upperpart of the boiler, its ends preferably joining or being in contact withthe forward ends of the longitudinal strips 22, and, thirdly, atransverse strip 24, interposed between the rear wall portion 16 and therear head of the boiler above the tubes 13 and extending across the rearhead, its ends joining the rear ends of the strips 22. The strip 24 ispreferably doubled or folded along its center, its folded edge beingsecured in the wall 16, while one of its free edges is bent upwardly andthe other downwardly, the said edges resting on the boiler-head, asshown in Fig. 2.

Around the various openings in the arch 15 for the steam-pipe 25, themanhole 26, and the safety-valve connection 27 I provide gaskets orannular packings 28 of asbestos, these gaskets surrounding the saidopenings and being interposed between the arch and the top of theboiler, so that they cooperate with the packing-strips above describedin maintaining the dead-air space between the upper portion of theboiler and the upper portion of the setting.

It will be seen that the various asbestos packing-strips or cut-oil'snot only confine the air in the air-space 21, but also prevent directcontact between the boiler-shell and the heated brickwork.

It often happens that when the boiler is first blown oil the brickworkin contact with the boiler communicates such a degree of heat to theboiler-shell that foreign matter in the water is liable to be burnedonto the boiler-shell by the heat thus communicated, this resulting inserious damage to the boiler. The dead-air space confined, as described,in contact with the upper portion of the boiler keeps the steam in theboiler at the highest possible temperature of saturated steam, the deadair reducing to the minimum the radiation or escape of heat from theupper portion of the boiler-shell. The gaskets 28 are preferably formedas flanges on the lower ends of sleeves or collars 29, of asbestos,which extend through the openings in the brickwork. These collars may beconfined by bands 30, of sheet metal or any othersuitable confiningmeans.

3 1 represents a feed-water-supplypipe having branches 32 32, Fig. 1,communicating with feed-water-heating conduits extending along the innersides of the side walls 14 of the setting, said conduits includingsinuous portions having a plurality of return-bends including a lowermember 33, connected by a pipe 34 with one of the branches 32, and anupper member 35, connected by a pipe 36 with the rear head of theboiler, the pipe 36 having an inclined extension 37, extending crosswiseof the boiler, as shown in Fig. 4, and entering the boiler preferablyjust below the line of the upper row of tubes 13 therein, as shown inFig. 4. The sinuous portions of the feed-water-heating conductor arelocated in recesses 38 in the inner faces of the side walls 14, as shownin Fig. 3, so that the members of said sinuous portions are offsetoutwardly from the inner faces of the walls 14, forming the sides of'thefire-box. Hence the feed-water-heating conduits are out of the path ofthe lines of convected heat rising from the'fire-box to the boiler.Consequently they do not absorb heat to the detriment of the generationof steam in the boiler, but simply absorb such heat as would otherwisebe absorbed by the side walls of the casing, and therefore wasted. Thesaid sinuous portions of the feed-water heaters are free to sliplongitudinally, so that free expansion and contraction of the feed-waterheaters is permitted, the lower members 33 of the feedwater heatersresting loosely upon the lower edges of the recesses 38 and being freeto slip thereon. The members of the sinuous portions of the feed-waterheaters are connected together by means of clamping-plates 39, placed onopposite sides of said members and united by transverse bolts, the lowerends of the clamping-plates being curved to form jaws 40, engaging thelower members 33 of the feed-water heaters.

41 represents a circulating-pipe which extends downwardly from thebottom of the boiler and is connected with the feed-water heaters abovedescribed in such manner that when the supply of feed-water through pipe42 and vertical pipes or branches 44 connecting the branches 43 with theportions 34 of the feed-water heaters. The branches 43 are provided withcheck-valves 45, which open outwardly from the boiler. When the feedwater-supply pipe 31 is closed, the checkvalves open and permit a flowof Water from the boiler through the pipe 41 and the describedconnections to the feed-water heaters. When the feed-water pump is inoperation, the pressure of the feed-water on the check-valves closes thesame, so that there is no circulation through the pipe 41 and itsbranches.

To permit the convenient blowing-off of the boiler and of the feed-waterheaters, I provide a blow-off conduit 46, having branches 47 47, whichare connected with the pipes 44 44, and a branch 48, which is connectedwith a branch 49 of the circulatingpipe 41. The branches 47 47 and 48are provided with suitable valves. When the valves in the branches 47 47are opened, the feedwater heaters may be blown off, and when the valvein the branch 48 is opened the boiler may be blown off through the pipe41 and its branch 49. The openings in the rear wall of the setting,which accommodate the various pipes passing through said wall, areprovided with bushings 50, Fig. 2, of asbestos, which permit such playof said pipes as is required for expansion and contraction and at thesame time maintain tight joints around the pipes.

The side walls 14 of the setting are provided at opposite sides of thethroat 18 with inwardly-projecting buttresses or flame-deflsctars 51,which contract the upper portion of said throat, as shown in Fig. 4. Theobject of these deflectors is to cause a uniform distribution of theproducts of combustion through the boiler tubes or flues 13 and pre ventall or the greater part of the products of combustion from passingthrough the upper tubes to the exclusion or avoidance of lower tubes,which is the material tendency when there are unobstructed spacesbetween the upper portions of the side walls of the setting and the rearhead of the boiler. The inner ends of the deflectors 51 are within abouttwo inches of the rear head of the boiler, so that they permit onlyportions of the products of combustion to pass directly from the sidesof the setting to the upper tubes of the boiler. Other portions of thesaid products are forced by the deflectors to pass into the lower tubes,so that an equal distribution is insured.

'I he bridge-wall 20 is provided with an airconduit 52, whichcommunicates with the ash-pit under the grate 53 and receives heated airtherefrom, the said conduit extending to the top of the bridge-wall. Theupper end of the conduit is partially closed by a block 54, havingnumerous circular perforations 55, which distribute the air and cause itto emerge from the top of the bridge-wall in numerous jets or streams.This perforated block or plate, which I term an Argand burner, is awell-known device and is shown in Letters Patent heretofore issued tome. I have improved the said Argand burner, however, by inserting in theorifices 55 obstructions 57, adapted to restrict the area of theopenings and to form numerous narrow slits or crevices through which theair is compelled to pass in minutely-subdivided jets.

In practice the obstructions 57 may be erdinary cut nails which aresubstantially rectangular in cross-section and are dropped into theorifices 55 until their corners bear upon the, walls of the orifices.The central portions of the orifices are thus filled, and theair-outlets are restricted to the narrow crevices between the surfacesof the nails and the walls of the orifices.

It will be observed that the rear bends of the feed-water-heatingconduits are located directly above the bridge-wall, so that the lengthof the stretches of the conduits between the "front and rear bends islimited to substantially the length of the lire-box. I find that thislimitation of the length of the feed-water-heating conduits is veryimportant, because it reduces to the minimum the frictional resistanceto the flow of feed-water to the boiler and increases to the maximum therapidity of the flow. This relatively rapid flow prevents the formationor the accumulation of masses or bubbles of steam in the conduits, andtherefore prevents the liability which exists of the burning out of themetal of the conduits when steam is present in bubbles cr masses in theconduits, in which case the portions of the conduits which are filled bythe steam are subject to rapid deterioration by the external heat, suchportions often becoming red hot. It is not safe to have free steam orwater at the temperature of saturated steam in feedwaterheating pipeswhich are exposed externally to the heated productsof combustion in afire-box, because the portions of the pipes subjected to suchtemperature rapidly deteriorate and are destroyed. Conduits limited inlength to substantially the length of the -lire-box, as here shown, arefree from liability to deterioration and destruction by heat.

A boiler, a casing or setting therefor having longitudinal recesses inits walls at opposite sides of the boiler, and offset outwardly from theinner surfaces of the sides of the firebox, the bottoms of said recessesforming substantially horizontal shelves or seats extending lengthwiseof the lire-box, and located outside the inner surfaces of the sides ofthe fire-box, return-bend feed-water-heating conduits located in saidrecesses, the lower members of said conduits resting on said shelves,and being adapted to expand and contract longitudinally thereon, clampsengaged with the said lower members, and supporting the upper members,whereby the upper members are permitted to expand and contract with thelower members, the latter being protected by the shelves against injuryfrom the heat of the tire, and connections between the upper members ofsaid conduits and a portion of the boiler higher than the conduits, therear bonds of the conduits being located adjacent to the bridge-wall, sothat the length of the longitudinal members of the conduit-s is limitedto substantially the length of the fire-box, and to the region ofconvected heat, wh reby the [low of feed-water through said conduits isfacilitated, and the formation of steam-bubbles therein is prevented,substantially as set forth.

In testimony whereof I have affixed my signature in presence of twowitnesses.

SIDNEY SMITH.

Witnesses:

C. F. BROWN, 1 IV. PEZZETTL

